Even if you could rip at the raw 24bpp RGB output and streaming audio, you are talking 356MByte/s (20GByte/m) of data for 1080p. People want the original stream

Even if you could rip at the raw 24bpp RGB output and streaming audio, you are talking 356MByte/s (20GByte/m) of data for 1080p. People want the original streams because they have already been nicely compressed. Now sure, you can then recompress this stream, if your CPU is able to compress it in real time as Netflix sends it to you. You'll double your compression artifacts, and any dropped frames compensating for your CPU speed or bandwidth will be lost forever. The end result will probably be between VHS and camrip in terms of quality. If someone really wants a rip, it's easier to get the decrypted form from a DVD or Bluray. Plenty of people have already done the work packaging most stuff like this anyway.